The party now intends to push the Scottish Government further to win its support for future budgets, with co-convener Patrick Harvie saying progressive taxation was "the only way" the SNP could expect Green support.

First Minister Nicola Sturgeon used her programme for government speech to say she was open to starting talks with parties on "responsible and progressive" use of taxation.

Harvie told delegates: “Greens are leading the change in so many ways, but on income tax it's our progressive proposals that have truly shifted the debate.

"With the powers Scotland has over rates and bands we can do so much more than simply tweak the basic rate, as some parties have suggested. We can instead cut tax for low earners, raise it for high earners, and altogether generate extra funds for public services.

“Our MSP group has already achieved a lot this year, on everything from young carers and child protection to fracking and publicly owned energy, and we're determined to keep pushing the minority SNP Government in the direction of a fairer Scotland and a clean economy.”

He also called for public sector pay to rise above inflation after years of it being capped at one per cent.

Maggie Chapman, the Scottish Greens' other co-convener, said the SNP had taken many ideas from the party.

“For years, Green councillors and MSPs have called for socially owned energy companies. I’m delighted that the Scottish Government has decided that this is possible after all.

"I’m only sorry the people of Edinburgh have had to wait ten years for the ability to buy not for profit energy, since we first proposed it.

“Similarly, we have argued for a national investment bank to support the kind of socially transformative changes such as those to community renewable energy. And we have been campaigning to bring our railways back into public ownership for years. Finally, it looks as though we might be getting somewhere on this.

“At first they laughed at us. Then they fought us. Then they put it in the Programme for Government. Nicola, there are plenty of other good ideas in our manifesto - feel free to nick them too.”